RESEARCH SUMMARY

  • Title: Rate of torque and electromyographic development during anticipated eccentric contraction is lower in previously strained hamstrings

  • Author/s: Opar (@davidopar), Williams (@drmorgs), Timmins (@ryan_timmins), Dear, Shield (@das_shield)

  • Year: 2013

  • Question: Does prior injury have an effect on myoelectrical activity of the hamstrings during tasks requiring high rates of torque development?

  • Key Takeaway: Previous HSI does indeed have a negative effect on RTD and impulse, with myoelectrical activity reductions interestingly confined to the biceps femoris long head (BFlh).

  • Summary: Recreational athletes with a history of unilateral HSI participate in a isokinetic dynamometry protocol with sEMG taken as a measurement. During slow eccentric contractions, lower rates of force development and impulse were observed in the injured limb compared to uninjured contralateral limb.

    Lower myoelectrical activity was confined to the biceps femoris long head. What are the implications for future hamstring rehabilitation practices?

    Key Findings: 

    • Previously injured hamstrings displayed lower rate of torque development and impulse during slow maximal eccentric contraction compared to the contralateral uninjured limb
    • Lower myoelectrical activity was confined to the biceps femoris long head.
    • Regardless of whether these deficits are the cause of or the result of injury, these findings could have important implications for hamstring strain injury and re-injury.